Periodic Table of Chemical Elements

2019 is the International Year of the Periodic Table of Chemical Elements (IYPT 2019)!

Let's get ready to celebrate!

Countdown to IYPT!

At the American Chemical Society (ACS), our vision is to improve people’s lives through the transforming power of chemistry. This year marks the 150th anniversary of the publication of Mendeleev’s Periodic Table of Chemical Elements in 1869. In celebration of this momentous occasion, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) officially proclaimed 2019 as “The United Nations International Year of The Periodic Table of Chemical Elements,” or "IYPT 2019."

ACS and chemical societies around the world will be celebrating throughout the year. IYPT celebrations will include contests, technical programming, themed gifts and giveaways, public engagement campaigns, and more.

The mission of the ACS is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. Join us as we show how chemical elements are central to "linking cultural, economic and political aspects of the global society through a common language, whilst also celebrating the genesis and development of the periodic table over the last 150 years."

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Submit information about your IYPT-related events here!

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See upcoming IYPT and periodic table events and find tips for hosting your own event!

Educational Resources




I’ve been used as a murder weapon.

Chemical Elements History Timeline

Interactive Periodic Tables from Around the Web

International Union of Pure and Applied Chemistry


Royal Society of Chemistry (RSC)

Fast Facts, By The Numbers


Discovered Elements of the Periodic Table


Elements Named After 16 Scientists,
Including Mendeleev


Elements Named After Women:
Lise Meitner (Meitnerium) and Marie Curie (Curium)

Donna Nelson

Did You Know?

In 1876 John Draper was the first president of the American Chemical Society and a pioneer of photography, taking the first photograph of the moon and one of the first photographs of a living person.